Transparent container inspection apparatus

ABSTRACT

Apparatus which will inspect containers for defects such as spikes, birdswings, and undesired flaws in the walls which render containers commercially objectionable. The apparatus operates to move containers in series and spaced relation through an inspection station where a background lighting is established to illuminate an area of each container larger than the field to be inspected. Opposite the source of light is an image-forming surface or mirror which directs the illuminated container image to an inspection unit which rotates the image to evaluate the overall evenness or uniform background lighting effect and photocells react to dark spots or areas usually caused by spikes, birdswings and flaws which upset the uniformity of the light in the area of the container being inspected. When a dark spot of the smallest detectable size, or a foreign body capable of changing or effecting the illumination is detected by the photocells, the container in which the change or effect occurs is rejected.

United States Patent 3,479,514 11/1969 Kidwell........................ 3,267,796 8/1966 Mathias [72] Inventors MomlrBabunovic DesPeres;

[21 1 pp No Bridgemn both 0! Primary Examiner-James W. Lawrence [22] Filed Mar 11 1970 Assistant Examiner-l C. Nelms [45] Patented Dec 21]971 Att0rneyGravely, Lieder & Woodruff [73] Assignee Berry-Wehmlller Company Louis ABSTRACT: Apparatus which will inspect containers for defects such as spikes, birdswings, and undesired flaws in the [54] TRANSPARENT CONTAINER INSPECTION walls which render containers commercially objectionable. APPARATUS The apparatus operates to move containers in series and 12 clams, 8 Drawing Fm spaced relation through an inspection station where a background lighting is established to illuminate an area of [LS- B, each container larger than (he to be inspec[ed Opposite 209/1 1 250/222 the source of light is an image-forming surface or mirror which directs the illuminated container image to an inspection unit Int. 1307c 5/342 [50] Field of 209/111]; which mums he image to evaluate the overall evenness or 250/221 R, 222 R, 223 B, 224

uniform background lighting effect and photocells react to dark spots or areas usually caused by spikes, birdswings and flaws which upset the uniformity of the light in the area of the [56] References Cited UNITED STATES PATENTS 6/1965 Wyman 4/1962 Seavey 6/1967 Sorbie container being inspected. When a dark spot of the smallest 209/1 11.7 detectable size, or a foreign body capable of changing or ef- 209/1 1 1.7 fecting the illumination is detected by the photocells, the con- 7 tainer in which the change or effect occurs is rejected.

PATENTED DEC?! I971 SHEET 1 [IF 3 PATENTEU BEC21 ran SHEET 2 OF 3 CO v FIG.2

PATENTEDUEIIZI l8?! 3 629595 SHEET 3 OF 3 FIG.5.A

TRANSPARENT CONTAINER INSPECTION APPARATUS SUMMARY OF THE INVENTION This invention is directed to apparatus, and to a method of practical application of such apparatus, for detecting a wide range of flaws in glass, transparent or translucent containers.

In the glass-container-manufacturing art certain flaws do occur and in such event the container is not acceptable for commercial use. The most objectionable flaws are spikes" and birds wings." In spike flaws a small filament of glass projects inwardly from the wall of the container and would create a serious hazard if broken-ofi upon filling the container. Birdswing" flaws develop when, at the time of blowing, a fine filament of glass is drawn out and connects two spaced places on the internal surfaces of a container. This is particularly a problem with the flat or flask-type containers. These types of flaws refract light and usually can be made to show up as a dark spot or darkened area in an illuminated field of view of the container. Other types of flaws, likewise can be made to show dark or darkened areas which will affect the uniformity in the illuminated field of view.

In examining containers it is desirable to look at the maximum area within the useful margins of the container. At the margins, however, the curvature or shape will always cause light refraction in the viewing area. Thus, the area must be limited in this regard to avoid viewing the dark marginal portions which define the shape in silhouette of the container. Because of this light refraction, it is not useful to inspect the extreme curved marginal areas of a container.

The present invention is directed to apparatus for inspecting an image of a container for dark spots or areas, and for reacting to the detection of a dark spot or area to trigger a device which will reject the container exhibiting the dark spot or area.

The detection system employed includes a light source adjacent the inspection station and on one side of the path of travel of successive containers, an image viewing and transmitting reflector on the opposite side of the path of travel of the containers through the illuminated inspection station, and a flaw detection unit which is able to look at and rotate the image and respond to the presence of a dark spot that may be caused by flaws. The detector generates a suitable reject signal. In this arrangement, the image-transmitting reflector is an important component as it is used to reflect a predetermined area of the container image to be inspected and project that area of the container through a lens system which focuses the image on an array of photoelectric cells having a predetermined constant or fixed area over which the image of the container is rotated. The reflector is a mirror which may be flat, or it may be cylindrically concave or convex, depending on the shape of the container and the maximum area desired to be submitted for inspection. The lens system includes collimating and focusing lenses to reduce the container image to a circular area of view that is then directed upon the photocell array. The photocells include a plurality of AC cells that are sensitive to changes in light from one level to another, and are used for inspecting the containers, and a DC cell for sensing changes in the level of light intensity from a predetermined standard, so as to distinguish different color characteristics such as clear or amber containers, or to detect the drop in light level caused by foreign matter that would not show up as a dark spot.

In apparatus for inspecting containers for flaws it is an object of this invention to provide a source of illumination to light the containers to be inspected; reflective means to reproduce the lighted image of the containers; inspection means to scan said reproduced image for detecting a change in the light level caused by flaws, said inspection means including a plurality of photocells arranged in a common plane having a predetermined area; lenses adapted to project the reproduced image upon said photocells within the extent of the area established thereby; and flawed container reject means operatively responsive to said photocells detecting a flaw to reject such containers.

In apparatus for inspecting containers for flaws it is an object of this invention to provide a container inspection station; a source of light directed in a path toward the container station to illuminate the container therein and cause flaws to refract the passage of illumination and create dark spots; an illuminated container image display means in the path of the light beyond the container, said image display means predetermining the size of the container image to be displayed in relation to the dimensions of the container to be inspected; photocell-scanning means having a predetermined area of scan less than the area of the container image display; lens means between said container image display means and said scanning means operable to focus the container image on said scanning means and reduce the same to fit within the area of scan; and means adjacent said lens means to rotate the container image relative to said scanning means, thereby passing the image over said scanning means, thereby passing the image over said scanning means to detect the presence of dark spots or light affecting foreign bodies.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a container conveyor provided with the inspection and reject apparatus which illustrates a preferred embodiment as to physical arrangement of the several components;

FIG. 2 is a sectional elevational view taken along line 2-2 in FIG. 1;

FIGS. 3 and 3A are related schematic views of the components of the inspection means to illustrate the field of view when employing a flat reflector mirror to inspect a relatively short but wide container;

FIGS. 4 and 4A are related schematic views similar to FIG. 3, but showing the field of view for a convex reflector mirror which accommodates a taller container having about the same width as in FIG. 3; and

FIGS. 5 and 5A are related schematic views similar to FIG. 3, but showing the field of view for a concave reflector mirror which accommodates a narrow container of the height shown in FIG. 3A.

DESCRIPTION OF THE APPARATUS In FIG. I the apparatus includes a typical flat top conveyor 10 having the several plates ll thereof pivotally connected for articulation about suitable driving and driven sprockets (not shown). An adjustable position alignment guide 12 is suitably mounted over the conveyor to move each container C into a desired position relative to the margin 10a of the conveyor. The several articulated plates 11 ride over angle members I3 which support the margins and maintain the plates in a level position and prevents sag in the conveyor path.

The conveyor moves successive containers C through an inspection station which is defined by the following components: a light box I4 is adjustably carried in suitable tracks 15 so that it may be moved closer to or farther from the container line of travel. A commercial type of retroreflective interrogator device I6 is located (FIG. 2) above the box 14 so it may project a light beam onto a rebound mirror I7 which returns the beam to the photocell within the retroreflective interrogator. When the neck of a container first crosses the path of the light beam it creates a signal which initiates a timer in the control circuit. Thus, each container C is able to signal its entry into the inspection station and the inspection is performed in the time built into the control circuit. On the opposite side of the conveyor 10 from the light box 14 there is a viewer box or periscope 18 having a window 19 to admit light from box 14 passing through the container C upon a reflecting surface 20 which directs the illuminated container image into an inspection head 21.

The head 21 (FIG. 2) is similar to the embodiment shown in Wyman US. Pat. No.. 3,l9l,733, granted June 29, 1965, wherein a lens and prism system is coupled to a photoelectric scanning means to inspect the interior of a container. In the present apparatus the head 2! includes a housing 22 enclosing a carrier 23 for a Dove prism 24, bearings 25 mounting the prism carrier 23 for rotation about the longitudinal axis of the prism 24, a member 26 supporting a plurality of collimating lenses 27, a second member 28 supporting a plurality of focusing lenses 29, and a member 30 carrying a plurality of photocells which include AC cells 31, 32 and 33 and a DC cell 34. The prism 24 is rotated by a motor M mounted in or adjacent the head 21 and connected by belt 35 to the prism carrier 23.

While not shown herein, the photocells 31, 32, 33 and 34 are associated with a circuit arrangement of the character disclosed in said U.S. Pat. No. 3,19 l ,773 and such circuit triggers the operation of a container reject device 36 (FIG. 1) which forces an undesirable container off conveyor 10. The reject device 36 is provided with a pusher arm 37 which is actuated by the push rod 38 in known manner of operation.

In FIG. 2, the light box 14 is provided with a light source 39 which directs the light onto a reflector surface 30 positioned at a suitable angle to turn the light into a horizontal direction. The light passes through a window provided with a Fresnel lens or diffuser 41 and an exterior clear cover glass panel 42. This organization provides a well diffused source of light having high brilliance and a substantially even distribution of the light for back lighting each container C. The box 14 is adjustably mounted on tracks so that it may be moved horizontally toward or away from the conveyor 10.

The purpose for adjusting the position oi the light box 14 with its light source 39 is to obtain compensation in the container illumination so that the defects being sought can be brought to optimum prominence, while reducing the interference caused by variations in wall thickness from container to container. Certain wall thickness conditions show up to the photocells as defects when that is not really the case. By moving the light box 14 closer to the path of container movement as defined by the conveyor 10, the wall thickness effects can be phased out to the extent necessary to check false responses by the photocells. Light box adjustments will effect corrections also for tuning out molded lettering and other markings that are formed in or on containers, such as manufacturers identification symbols and the like, but which are not defects requiring rejection.

In the views of FIGS. 3, 3A, 4, 4A, 5 and 5A it is to be understood that the box or periscope 18 is positioned to produce an image of the side of each container. Thus, in FIGS. 3A, 4A and 5A the position of the container is, for clarity of illustration, turned ninety degrees (90) to the corresponding positions respectively in FIGS. 3, 4 and 5. This manner of illustration is believed necessary for convenience in setting forth the description that follows.

As can be seen in FIG. 2 and more in detail in FIGS. 3 and 3A, one form for the reflective means is a fiat mirror set at a suitable angle (approximately 45 to the horizontal) and aligned with the axis of the lens system to direct the light in a path toward the lens system in detection head 21 where it is first intercepted by the collimating lens 27. It is understood that the lens system 27 and 29 transmits a circular field of light upon the constant area included in the array of photocells in member 30. The perimeter filaments A of the light. envelope containing the container image to be inspected constitutes a cone-shaped beam diverging from lens 27. The flat mirror cuts the cone-shaped beam at an angle such that the perimeter filaments A mark the useful limits of inspection of the container. As a result, the photocells are able to inspect the area represented in FIG. 3A as a circular area 43 on the near side of the container C. By proper selection of lenses and size of the mirror 20, the horizontal axis X of the area 43 can be sized to cover the desired width of the container C which just excludes its curved, light-distorting margins. The vertical axis Y of this area 43 is equal to the horizontal axis X. In this and the other similar views of the drawings, it is convenient to refer to the horizontal width of the field of view as the X-axis, and to refer to the vertical height of the field of view as the Y axis.

In this manner, spikes, birdswings and other defects D (FIG. 2) can be easily detected since any of these defects changes the response of one or more of the photocells 31, 32 and 33, depending on its location in the field of area 43. The lens system is selected so that the effective focal length of lens 27 picks up the container image from the reflector and lens 29 produces a sharp focus of the image at the face of member 30 where the photocells are mounted to cover a fixed area. Rotation of the Dove prism 24 causes the lighted image 43 of the container to rotate so that a complete scan is achieved by the photocells. The presence of a defect or a foreign body affects one of the photocells which causes a signal to be transmitted to the reject means 36 through a suitable circuit contained in box 44 suitably mounted, for example, adjacent the head 21. The circuit in box 44 is more particularly set forth in said U.S. Pat. No. 3,191,773 and need not be described here.

An expanded field of view 45 may be obtained for a taller container C, as in FIGS. 4 and 4A, but utilizing a cylindrically convex mirror 20A whose longitudinal axis is parallel to the X- axis of the field of view. Since, in this case, the perimeter light filaments A strike the convex mirror 20A at different angles from those in FIG. 3, the field of view 45 is in the shape of an ellipse having a major axis directed vertically along the Y-axis of the container C and a minor axis directed along the X-axis within the width of the container C. For the container C having the same width as container C in FIG. 3A, the X-axis will be the same size, the field of view is expanded only in the direction of the vertical or Y-axis.

In FIGS. 5 and 5A there is shown a cylindrically concave mirror 208 which is positioned with its axis Z-Z in the plane which contains the Y-axis of the field of view, but at an angle so that these axes converge at a point someplace below the area to be inspected. In FIG. 5 the mirror 208 has its near margin partly broken away so that its curvature may be seen at the far side. In this arrangement, the field of view 46 is elliptical with its major axis in the vertical direction of the Y-axis of the container C" and its minor axis in the horizontal direction of the X-axis. If the container C" is as tall as container C in FIG. 3A but narrower, the height along the Y-axis will not change, but the width along the X-axis will be reduced to fall within the desired width of inspection of the container C.

In order to accommodate various sizes or heights of containers, the box or periscope I8 is adjustably mounted (FIG. 2) to slide relative to a fixed sleeve 49 carried by the head 2]. Suitable holes 50 are provided in both the sleeve 49 and box 18 to receive a locking pin (not shown). The rebound mirror 17 is fixed in position adjacent the sleeve 49 on a suitable bracket 51 attached to the head 21 in position to be aligned with the interrogator device 16 carried by the housing 44 for the control circuit means.

In FIG. 2 it is to be understood that member 26 carries a plurality of collimating lenses 27 and is operatively connected to a shaft 47 having a control knob 48 at its outer end. The member 28 carrying a plurality of focusing lenses 29 is also operatively connected to the upper end of shaft 47, and the member 28 pivots from the top face of the fixed structure which supports the bearings 25 for the Dove prism 24. This arrangement is similar to that shown in said Wyman U.S. Pat. No. 3,191,773, and needs no further explanation.

It is further to be understood that when inspecting extremely tall containers or containers having long necks it is necessary to elevate the inspecting head 21 so these types of containers will pass under the head. When the head 2l is elevated the periscope box 18 requires adjusting to locate the viewing window 19 in the proper place. Thus, the periscope box 18 needs to be elongated which moves the reflecting means 20, or 20A or 208 further down on the cone of light marked by the perimeter A. The result is that the lens 27 must be changed to narrow the cone perimeter A so it stays within the periscope box 18 and the lens 29 must be changed to obtain a sharp focus at the photocells. Such lens adjustment is obtained by swinging the lens-carrying members 26, and 28 at knob 48.

Should a container have an exceptionally wide or fat body the elliptical field of view of the image in FIG. 4A may be oriented with its major axis in the horizontal. This is accomplished by turning the reflective mirror A ninety degrees (90) on its pivot support 52 in the bearing support 53. In like manner the reflective mirror 205 may be angularly oriented on its pivot support 54 in bearing support 55. If the coordinates or axes of the field of view of the container image require some other alignment, the mirrors may be partially turned. It is also contemplated that a reflective mirror combining portions that are flat and portions concave or convex may be employed to shape the image of the container as desired. A showing of this variation is not believed necessary.

OPERATION OF THE APPARATUS The principle which this apparatus embodies is one in which the area of view for the photocells in member remains substantially constant and is always circular so that the X and Y- axes of the field of view are always equal in length. Then lens system in cooperation with the reflector means in the periscope 18 therefore allows the image of the container field of view for inspection purposes to be altered in size and shape. Primary examples of these features of the apparatus are shown in the views of FIGS. 3A, 4A and 5A where it is noted that the field of view may be substantially circular, or it may be elliptical by expanding the Y-axis with a cylindrically convex reflector, or it may be elliptical but with a reduced X-axis upon insertion of a cylindrically concave reflector. The aim is to inspect the areas of containers of various sizes with a constant area of photocells and this is accomplished by selection of reflectors, adjusting the length of the periscope box 18, changing the elevation of head 21, and changing the lenses to produce a sharp image of constant circular area upon the plane occupied by the photocells.

While the present apparatus is not adapted to inspect a run of containers of random width or height, it is especially adapted to accommodate a wide range of container sizes where each run is limited to a given container size. Selection of the size and shape of the reflective mirrors 20, 20A or 208, the length of the periscope box 18, the position of head 21, and the selection of lenses 27 and 29 will produce the desired results for inspecting commercial types of light-transparent containers. It. has been pointed out that a flat mirror 20 will cover a circular field of view which is suitable for containers that are short and wide enough to present a field of view within the greatest area of probability for defects to occur. A convex mirror 20A will cover an elliptical field of view for containers that may be as wide as the short containers but which are taller. In this instance, the size of the X-axis may be substantially the same as for the flat mirror 20, and the Y-axis will be expanded due to the convex shape. When tall but narrow containers are to be inspected, a concave mirror 20B is used so that the X-axis can be reduced without changing the Y-axis, or by proper selection of concave mirror 203 the X- and Y-axes may both be reduced. Other shapes of images may be inspected by combination of flat and convex or concave reflectors, all as pointed out herein.

It should now be understood in what manner the present apparatus carries out the principle of the invention. In each of the principal examples shown and described the field of view for inspection by the photocells is maintained substantially constant and circular in shape, whereas the reflective mirror permits the image of the field of view of the container to have the desired shape in the X- and Y-axes, or in some angular orientation of these axes, to include the greatest area of the container to be inspected for defects. The Dove prism in the lens system allows the container image to be rotated so that a complete scan of the image is achieved while the containers are in motion. For containers having exceptionally wide bodies the time for inspection may be increased so that scan will cover the field of view while the container is in motion. The broad scope of the invention is intended to include means to move a stream of light-transparent containers between a source of side lighting for the major area of the container and flaw-detecting means opposite the light source, with the detecting means composed of components operative to shape and size the image of the critical area of the container for maximum area of scan by light-responsive sensors and to rotate the image relative to the sensor. The character of flaws to be detected by this apparatus occur at generally known areas in glass containers or bottles and it is this area that comprises the critical area for scanning. The varieties of shapes and sizes of containers requiring inspection generally rules out container rotation so complete inspection of the critical area is obtained by rotating the image without at the same time having to rotate other components of the apparatus.

We claim:

1. Apparatus for inspecting containers for flaws comprising: conveyor means to move the containers in upright positions horizontally through an inspection zone; a source of illumination at one side of the inspection zone, said illumination source back lighting the container in the area to be inspected; a plurality of photocells arranged in a common plane having a predetermined flaw viewing area and being fixed relative to the container moved through the inspection zone; and container lighted area projection means between said photocells and the side of the container opposite to said back-lighting source of illumination, said projection means including a rotary prism effective to rotate the container lighted area image before said photocells, and mirror means positioned between said prism and the side of the container opposite to said backlighting source of illumination, said mirror projecting the lighted image of the container into said prism, said mirror means altering the size and shape of the lighted image of the container to substantially match the predetermined flaw viewing area of said photocells.

2. The apparatus set forth in claim 1 wherein said mirror means to scan the reproduced lighted image of the containers is a flat mirror assuming a predetermined angle to the direction of the light source so as to reflect the lighted image of the containers into said rotating prism.

3. The apparatus for inspecting containers for flaws as set forth in claim I wherein said mirror means is a cylindrically convex mirror whereby the X- and Y-axes of the container image are caused to be unequal.

4. The apparatus for inspecting container for flaws as set forth in claim I wherein said mirror means is a cylindrically concave mirror having its axis in the plane of and at an acute angle to the vertical Y-axis of the container field of view, whereby the X- and Y-axes of the container are caused to be unequal.

5. Apparatus for inspecting containers for flaws comprising: means to move containers in upright attitude and horizontally along a predetermined path; container image viewing means defining a container inspection station for said container-moving means; a source of light adjacent one side of said inspection station to illuminate the containers from one side thereof and create a lighted image; said image viewing means being at the side of said container-moving means opposite said light source for reproducing the container image in a predetermined configuration inclusive of the area of a container to be inspected for flaws; and container image inspection means to receive and scan the reproduced container image for flaws, said inspection means including light-responsive means presenting a substantially fixed area to the lighted image of the container, container image projection means between said image viewing means and said light-responsive means effective to size the container image to fit within the fixed area of said light-responsive means, said projection means including a rotary prism for rotating the container lighted image; and means to reject a flawed container operatively responsive to changes in the level of illumination detected by said lightresponsive means.

6. Apparatus for inspecting containers for flaws as set forth in claim 5, wherein said image-viewing means reproduces the container image in a configuration in which the X- and Y-axes are substantially the same and said image projection means fits said circular container image within the fixed area of said light-responsive means.

7. Apparatus for inspecting containers for flaws as set forth in claim 5, wherein said image viewing means reproduces the container image in a configuration in which the vertical axis is unequal to the horizontal axis, and said image projection means converts the image configuration into a circular configuration to fit within the area of said light responsive means.

8. The apparatus for inspecting containers for flaws as set forth in claim wherein said image-viewing means reproduces the container image with a configuration in which the Y-axis is greater than the X-axis, and said image projection means fits the configuration of the the container image within the fixed area of said light-responsive means.

9. ln apparatus for inspecting flat sided flask-type containers for flaws: means to support a container with its widthwise axis generally horizontal and its lengthwise axis generally vertical; means to illuminate the entire container from one flat side and cast an image thereof: mirror means adjacent the opposite side to reproduce a selected portion of the flat side of the container image with predetermined widthwise and lengthwise axes; light sensitive means having an effective area with constant widthwise and lengthwise axes; and image projection means between said light sensitive means and said container image-reproducing mirror means to conform the widthwise and lengthwise axes of the selected container image to said constant widthwise and lengthwise axes for said lightsensitive means, said image projection means including a rotating Dove prism to rotate the container image relative to said light-sensitive means.

10. The apparatus as set forth in claim 9 wherein said means to reproduce a selected portion of the container image causes the widthwise and lengthwise axes to be equal.

1]. The apparatus of claim 9 wherein the means to produce a selected portion of the container image causes said widthwise and lengthwise axes to be unequal.

12. The apparatus set forth in claim 9 wherein said means to reproduce a selected portion of the container image causes said lengthwise axis to be greater than said widthwise axis. 

1. Apparatus for inspecting containers for flaws comprisIng: conveyor means to move the containers in upright positions horizontally through an inspection zone; a source of illumination at one side of the inspection zone, said illumination source back lighting the container in the area to be inspected; a plurality of photocells arranged in a common plane having a predetermined flaw viewing area and being fixed relative to the container moved through the inspection zone; and container lighted area projection means between said photocells and the side of the container opposite to said back-lighting source of illumination, said projection means including a rotary prism effective to rotate the container lighted area image before said photocells, and mirror means positioned between said prism and the side of the container opposite to said back-lighting source of illumination, said mirror projecting the lighted image of the container into said prism, said mirror means altering the size and shape of the lighted image of the container to substantially match the predetermined flaw viewing area of said photocells.
 2. The apparatus set forth in claim 1 wherein said mirror means to scan the reproduced lighted image of the containers is a flat mirror assuming a predetermined angle to the direction of the light source so as to reflect the lighted image of the containers into said rotating prism.
 3. The apparatus for inspecting containers for flaws as set forth in claim 1 wherein said mirror means is a cylindrically convex mirror whereby the X- and Y-axes of the container image are caused to be unequal.
 4. The apparatus for inspecting container for flaws as set forth in claim 1 wherein said mirror means is a cylindrically concave mirror having its axis in the plane of and at an acute angle to the vertical Y-axis of the container field of view, whereby the X- and Y-axes of the container are caused to be unequal.
 5. Apparatus for inspecting containers for flaws comprising: means to move containers in upright attitude and horizontally along a predetermined path; container image viewing means defining a container inspection station for said container-moving means; a source of light adjacent one side of said inspection station to illuminate the containers from one side thereof and create a lighted image; said image viewing means being at the side of said container-moving means opposite said light source for reproducing the container image in a predetermined configuration inclusive of the area of a container to be inspected for flaws; and container image inspection means to receive and scan the reproduced container image for flaws, said inspection means including light-responsive means presenting a substantially fixed area to the lighted image of the container, container image projection means between said image viewing means and said light-responsive means effective to size the container image to fit within the fixed area of said light-responsive means, said projection means including a rotary prism for rotating the container lighted image; and means to reject a flawed container operatively responsive to changes in the level of illumination detected by said light-responsive means.
 6. Apparatus for inspecting containers for flaws as set forth in claim 5, wherein said image-viewing means reproduces the container image in a configuration in which the X- and Y-axes are substantially the same and said image projection means fits said circular container image within the fixed area of said light-responsive means.
 7. Apparatus for inspecting containers for flaws as set forth in claim 5, wherein said image viewing means reproduces the container image in a configuration in which the vertical axis is unequal to the horizontal axis, and said image projection means converts the image configuration into a circular configuration to fit within the area of said light responsive means.
 8. The apparatus for inspecting containers for flaws as set forth in claim 5 wherein said image-viewing means reproduces the container image with a cOnfiguration in which the Y-axis is greater than the X-axis, and said image projection means fits the configuration of the the container image within the fixed area of said light-responsive means.
 9. In apparatus for inspecting flat sided flask-type containers for flaws: means to support a container with its widthwise axis generally horizontal and its lengthwise axis generally vertical; means to illuminate the entire container from one flat side and cast an image thereof: mirror means adjacent the opposite side to reproduce a selected portion of the flat side of the container image with predetermined widthwise and lengthwise axes; light sensitive means having an effective area with constant widthwise and lengthwise axes; and image projection means between said light sensitive means and said container image-reproducing mirror means to conform the widthwise and lengthwise axes of the selected container image to said constant widthwise and lengthwise axes for said light-sensitive means, said image projection means including a rotating Dove prism to rotate the container image relative to said light-sensitive means.
 10. The apparatus as set forth in claim 9 wherein said means to reproduce a selected portion of the container image causes the widthwise and lengthwise axes to be equal.
 11. The apparatus of claim 9 wherein the means to produce a selected portion of the container image causes said widthwise and lengthwise axes to be unequal.
 12. The apparatus set forth in claim 9 wherein said means to reproduce a selected portion of the container image causes said lengthwise axis to be greater than said widthwise axis. 